Two hand control for presses



July 6, 1943. E. DAVIS TWO-HAND CONTROL FOR PRESSES '4 Sheets-Sheet 1 Filed Jan. 5, 1942 4 m II////// 0/ 2 3 4 4 4 4 I 2 1 i: I. 5 8 v 4 w 7 9 3 ma 7 m B 9 m 6 w 5 l x a m p 9R5 v :3 w .VS mm 7 n a 2 T a u a. 2 3 m 3 .l a .w AM I e u l WWW Am m a L. 5 .HH l umml G H A'FT V- July 6, 1943. E. DAVIS 2,323,457

TWO-HAND CONTROL FOR PRESSES Filed Jan. 5; 1942 4 Sheets-Sheet 2 FIG. .3

' lzagg INVENTOR ERNEST DAVIS QMW A T'TY.

July 6, 1943. E. DAVIS 2, 5

TWO-HAND. CONTROL FOR PRESSE S Filed Janp 5 1942 4 Sheets-Sheet 3 39 3a. 45 36 37 24 I '9 ,4s'

INVENTOR ERNEST DAVIS ATTY.

July 6, 1943. E. DAVIS TWO-HAND CONTROL FOR PRESSES Filed Jan. 5, 1942 4 Sheets-Sheet 4 INVENTOR E RNEST DAVIS Patented July 1943 2,3:3, TWO HAND CO L FOB PBESSES Ernest Davis, Syracuse, NJY assignor to The,

Prosperity Company, Inc., Syracuse, N. Y., a corporation of New York Application January 5, 1942, Serial No. 425,675

12 Claims. (Cl. 192-431) This invention relates to two hand controls for presses, which include coacting pressing elements, as upper and lower pressing elements, one of which, as the lower pressing element, is

stationary in the normal operation of the press, 1

and the other has an operating movement into and out ofcoaction with the normally stationary element to close and open the press, and has for Figure 6 is a side elevation, partly broken away, of a press embodying-another modified form in which the retractable element is the one actu-' ated during the closing operation.

its object a two hand control mechanism, both I of which must be operated to eifect the closing of the press, and mechanism operated in conjunction with the two hand control and with the operating movement of the press to effect the retracting of one of the elements relative to the closing movement and during the closing opertractable element, and means controlled by the' out of operative position, unless both manuals are held operated until the press 'is closed or nearly closed to a safety position, or to such an extent that the operator can not get his hands between said elements or so that both hands must be kept occupied in operating the manuals until the press is closed to safety position.

-The'invention consists in the novel features and in the combinations and constructions herebeforethe upper element or head coacts with the lower pressing element.

Figure 3 is a view similar to Figure-.1 of a press, the press remaining closed for an indefinite period before opening, as a garment and laundry press, such a press having releasable holding means which holds the press closed.

Figure 4 is a diagrammatic view of the power system and control means. I Figure 5 is a detail view illustrating a modifled form of the holding means used in the garment and laundry press.

Figure 7 is a diagrammatic fragmentary view of the mechanism shown in Figure 6 showing the retracting mechanism as operated.

The invention comprises, generally, independently operable manuals, both of which must be operated jointly or in unison to control the actuation of the power actuating means for closing the press, power means for retracting the rerelease of either manual while the press is closing for energizing the motor of the retracting means for the retractable element.

In Figure 1, the invention is shown as applied to a press in'which the movable element or head moves into and out of coaction with the lower pressing element in one operation, without remaining closed, or a machine of the punch press type. In Figures 3- and 6, the invention is shown as applied to a machine, as a garment and laundry press, where the head or movable element remains in closed position for a period of time before being opened, and is openedby operating a release control member either by hand or by a timer. The release member is here shown as operated by hand.

In Figure 1, I designates the upper or movable pressing element or head, and 2 the lower retractable pressing element, the head I' being movable vertically along a suitable guide 3 on the frame 4 of the machine and carrying, a die 5 for coacting with the complemental die 6 on the retractable or lower pressing element 2. In machines of the punch press type, the head I is actuated by a shaft 1 suitably mounted in the frame of the machine and having an eccentric for actuating a connecting rod 8 which is connected to the head I. The shaft 1 is connected to and disconnected from a. power shaft, not shown, axially alined with "the shaft I through a clutch device operable to clutch and unclutch the shaft .1 from the; power shaft. When clutched thereto, the shaft 1 makes one complete revolution and hence one complete reciprocation of the head I, and this clutch heretofore has been engaged either by a rrlanual member or lever, or by a foot lever and disengaged automatically at the end .of each revolution of the shaft 1, the clutch being thrown in by the operation of a manual or manuals or the operation of a pedal, all as is known by-those,farniliar with 'punch presses.

In punch press constructions, after the head I has been, stared or the power has taken hold, by reason of the clutch being engaged, it has not been practical to stop the descent of the head I, and hence heretofore there has been an interval when the operator might get his fingers caught between the dies, even with a two hand control, after thepress starts in motion. This invention relates to a two hand control by which one of the elements shown in Figure 1 as the lower element 2 retracts, as shown in Figure 2, in the event the operator releases either or both hands while the head I is on its downward movement.

In the illustrated embodiment of my invention, as shown in Figure 1, I designates, generally, the clutch, this may be of any well known construction, and the clutch is operated by a motor I I. As, in this embodiment of the invention, the power for the motor II is a fluid under pressure, as compressed air, the motor II is a pressureoperated motor, usually of the cylinder and pis-- ton type, and the control members of the two hand control are valves. However, the invention is not limited to any particular type of power or motors and control members. The energizing of the motor II acts to throw in the clutch, and the clutchis thrown out automatically in the usual manner at the end of one revolution of the shaft 1. I2 and I3 designate the control members or valves of the two hand control system, and I4 and I5 the manuals. The valves I2 and I3 are illustrated as of the combined intake and exhaust type and connected in series in a feed line of a system with the pressureoperated motor II. Thevalve I2 includes 8. normally-closed intake valvehead I 5 and a normallyopen exhaust valve head I1 connected together, so that they act as a unit, the valve being selfreturnable to its normal position by a spring I8. The valve I3 is of similar construction, it having a normally-closed intake valve head I9 and a normally-open exhaust valve head 20, and a returning spring 2|. Upon operation of the manuals I4, I5, both valves are opened, so that air passes from a feed line 22 through the valve I2 and pipe 23 to the intake end of the valve I3, then through pipe 24 to the cylinder of the motor II to actuate the piston therein and through its rod 25 operate the clutch III to closed position, so that the shaft 1 is rotated, causing the head I to make one complete closing and opening movement or reciprocation.

, The retractable element 2 carrying the lower die 5 is mounted to have a vertical movement in a suitable guide 26 in the frame 4 and is normally stationary and retractable or movable vertically by a motor, which, in this embodiment of the invention, is a pressure-operated motor, as-

a cylinder 21 having a piston 28* therein. The rod 28 of the piston 28*- is connected to the pressing element 2 through suitable motion transmitting means, which is normally rigid to hold the lower element 2 stationary. This motion transmitting mechanism is here shown as toggle links 29, 30 pivoted together at like ends at 3| and at their outer ends at 32, 33 respectively to the lower pressing element I and to the frame 4. These toggle links are normally arranged in a straight locked position, or normally beyond a dead center line passing through the pivots 32, 33 and are shown as abutting against the stop at 34, so as to rigidly support the element I. When, however, the operator releases one or both manuals I4, before the press head by the manuals and by a control member operated by the shaft 1, the latter being a valve, because the system is pneumatic.

35 designates a control member operated by the shaft 1. It is shown as a valve of the combined intake and exhaust type having a normallyclosed intake valve head 36, an-exhaust valve head 31 connected together to act as a unit and a spring 38 returning the valve heads to their normal position. The casing of the valve 35 is connected to a feed line 39 and the valve is operated by the rotation of the shaft 1 by means of a cam 40 here shown as on the periphery of a fly wheel H on the shaft 1, the cam coacting with a follower or roller 42 carried by a lever 43 pivoted at 44 between its ends and having one arm thereof thrusting through a spring-pressed head 45 against the combined intake and exhaust valve members including the heads 31 and 38. The cam extends nearly half way around the fly wheel and the follower located normally at one end of the cam. Thus, when the fly wheel 4| starts at the beginning of its revolution, the cam 40 actuates the lever 43 to open the intake head and close the exhaust head of the valve 35 and the air will pass from the pipe 39 through the valve 35 and into the pipe 46. This pipe 46 communicates through branches 41 and 48 with normally open transfer chambers 49 and 50 in the casings of the valves I3 and I2 respectively. The transfer chambers communicate through transfer pipes 5I and 52 with a pipe 53 leading to the intake end of the cylinder 21, this pipe having a pressure-operated valve 54 therein provided with a restricted bleeder exhaust opening 55 for a purpose to be hereinafter referred to. The transfer chambers having normally open piston valves 55 and 51 therein respectively, which are operated to cover the po1ts in the chambers 49 and 50 from which the pipes 5| and 52 lead, when both manuals are operated, or in other words, these piston valves 56, 51 are operated respectively by the manuals I5 and I4 at the same time the manuals are operating the valves I3 and I2. Thus, upon the operation of the manuals I4 and I5, the pipes 52 and 5| are closed by the piston valves 51 and 56, and hence the air passing through the control valve 35 is cutofl' from passing to the cylinder 21.. If, however, the operator releases either hand from the manual I4 or I5, while the press head I is on its closing movement, for instance. suppose the operator releases the manual I4, then the piston valve 51 will be open and the air will 'pass from the pipe 45 through pipe 48, transfer 40 extends approximately half way around the fly wheel 4I, so that at the end of the closing move.- ment the control valve 35 will automatically close. The toggle will straighten under the action of a returning spring 58 and return the element 2 to its normal position, and the piston 25' toits starting position. The air exhausts slowly from the cylinder 21 through the bleeder opening 55 of the valve 54, so that the return movement of the element 2 and the toggle is dampened. During this retracting movement of the element 2, the shaft 1 continues to rotate and complete its revolution, and during the last half of its revolution,-the intake head of valve 85 closes and the exhaust head opens, so that the air in the pipes 46, 41, 48, transfer chambers 49, 58, pipes and 52 exhausts out through the valve 85 or is not trapped therein.

The manuals I4, I5 may be of any suitable construction, and their construction forms no part 01' the invention. Each manual I4 or I5 as here illustrated includes acasing or cylinder 59, a

piston 88 therein movable toward and from a plunger 8| and a finger-piece 82 guided in the outer end of the cylinder 59, and having a normally open valve 68,- which, when the fingerpiece is depressed, cles a port 84 extending lengthwise of the stem of the piston 88 and opening into the space 55 between the piston 88 andthe plunger 8|. The movements of the fingerpiece 62 and the plunger ii are against the action of suitable returning springs 66 and 81. Each plunger 8| thrusts against one arm of a motion transmitting lever 88, the other .arm of which thrusts against a cross-head 89 between the stem of the movable valve member of the control valve I2 or I3 and the stem of the piston valve 51 or 58 of the control valve I2 or I3. The motion of the lever 68 is against the action of a returning spring I8. Also, each cross-,head 69 is acted upon by a returning spring II.

In Figure 3, the two hand control mechanism is shown as applied to a press, as a garment or laundry press, in which the pressing elements are of the platen type and the press remains in closed position a period of time after being closed. The actuating mechanism for the press is shown as a reciprocating motor instead of a rotating shaft, as I. I2 and i3 designate respectively, upper and lower pressing elements, the upper pressing element or head being shown as carried by a lever 14 pivoted between its ends at I5 to a frame I6 of the machine, and as actuated by a cylinder and piston motor, the motion of which is transferred through the reciprocating piston rod and, toggle links to the head-carrying lever I4. TI designates the cylinder; 18 the piston therein having its rod I9 pivoted at 88 to the joint of a toggle consisting of links 8I. 82 pivoted at their outer ends respectively at 83 to the rear arm of the head-carrying lever I4 and at 84 to the frame near the base thereof. The cylinder and piston motor is single acting and the opening of the press is efiected. through a counterspring 85 connected to the rear arm of the head-carrying lever I4 and to the frame.

The flow of motive fluid or air to the cylinder II is controlled by a master valve 86 which in turn is con-trolled by the two hand control valves I2 and I3 operated by the manuals I4, I5 as in the construction shown in Figure l, but the air,'after it passes through the two hand control valves I2, I3, when the manuals are properly operated, passes to a pressure-operated device for opening a master or relay valve 88. As here illustrated, it

passes from the pipe 22 through control valve I2, 70

which acts upon a. slide 98 thrusting against the normally open exhaust valve head 9| to close the same when operated and open the normallyclosed intake valve head 92 of the master valve 85 5 this movement being against the action of a returning spring 93. The valve 88 is of the combined intake and exhaust type similar to the valve I2 or I3. The intake'end of the master valve 88 is connected by a supply pipe 94. When 10 the air enters the diaphragm chamber 8'! through the pipe 24, it thus opens the intake valve head 92 and closes the exhaust valve head 9|, permitting the air to pass from the feed line 94 through the valve 86 and pipe 95 to the intake end 1 of the cylinder 11 and actuate the piston therein,

to cause the press head I2 to close.

Means is provided to hold the master valve 88 open when the head 12 has closed to a safety position or has come downto nearly in contact with the pressing element I3 or the padding or work thereon. This means embodies the double diaphragm 88, 89, the space between these diaphragms being connected by a pipe 98 to a port 91 inthe side of the cylinder II and located to be passed by the piston I8, when it has traveled a predetermined distance on it power stroke, so that air can enter from the cylinder to the space between the diaphragms 88, 89 and hold the movable member of the relay valve 86 in its operated position. To open the press, the air is ex hausted from the space between the diaphragma- "88. 89 permitting the valve 86 to open and the air to exhaust back from the cylinder 11 back through the pipe 95 and the master valve, which is now in normal position, or with its exhaust valve head 9i open and its intake valve head 92 closed. The air is exhausted from between the diaphragms 88, 89

through a pipe 98 leading to a normally-closed;

self-closing, manually operable release valve 99 of any suitable construction and having a release or finger lever I 88.

The lower pressing element I8 is retractable in the event the operator releases either or" both manuals I4 or I5 before the head I2 has closed to a safety position. It is here shown as supported by a vertically slidable pedestal I8I in a suitable guide I 82 in the frame, and is supported and retracted by toggle links I83, I84 arranged in substantially the same manner as the toggle links 29, 38 (Figure 1), these toggle links being held in straightened position, as by a'spring I85 located in the cylinder I86 and thrusting against the piston I81, the rod I88 of which thrusts against the joint of the toggle'links I83, I84. The

intake end of the cylinder I86'is connected by a tion, the air will "pass from the main line 39- through the valve I89 out through the pipe 48 and out through either branch 41' or .48 and through either of the piston valve chambers 49 or 58, whichever happens to be open, and thence through either or bothpipes SI, 52 and pipe 53 to the cylinder I88 to actuate the piston therein to fold the toggle consisting of links 183,- I84 and retract the lower'pressing element I3 downwardly. The piston rod I9 is provided with a by a moving part of the actuating mechanism, as

rib or cam II which coacts with the follower in Figure 1, operation of both manuals I4, I

01' the lever 43 which operates the valve member of the valve I09 (Figure 3). However, this cam' or rib H0 is of such length that the cam passes or clears the follower during the power stroke of the piston I8, so that when the piston reverses and returns to its normal position, the lever rocks in the opposite direction from that in which it rocks during the power stroke of the piston, and hence does not operate the valve I09 during retrograde or return movement of the piston I0.

the cylinder 21 to actuate the piston therein to The lever '43 in Figure 3 is acted upon by a spring III but the piston I8 is retumed to its starting position during the opening of the pras by the action of the counterspring 85. Also, a returning spring II 2 acts on the toggle links 8|, 82. Thus, wher. the press has been operated and theoper ator removes one or both hands before the press closes, the pressing element I3 will retract downwardly and also the head will immediately open under the action of counterspring 85, the opening movement causing the valve I09 to shift, so that the exhaust head is open and hence 'the air can exhaust from the cylinder-,l06 back through the pipe 53, the casings of va1ves l3, I2, branches 41 or 48, a pipe 46 and out past open exhaust valve head in the valve I09, permitting the spring I05 to react to again straighten the toggle links I03, I04 and elevate the lower pressing element I3 to itsnormal position. The port 91 in the side of the cylinder 11 is located to be passed about the time the left end of the cam IIO on the piston rod I9 clears the follower on the operating lever 43 for the control valve I09.

In Figure 6, the pressing element, which is retractable relative to the closing movement, when either or both manuals are released before the press closes to a. safe position, is the upper pressing element instead of a normally stationary lower pressing element. In the construction here shown, one of the links of the toggle for transmitting the motion to the head-carrying lever 14 is shown as consisting of normally straightened toggle links, which are foldable by a cylinder and piston operating similar to the cylinder and piston I05, I01 (Figure 3). In Figure 6, one of the toggle links corresponding to the toggle links 8|, 82 (Figure 3) is composed of toggle links H5, H6 normally arranged in straightened position and operating in this position during the normal operation of the press. The control system is substantially the same as shown in Figure 3. Upon release of either or both manuals before the press head is closed to a safe position, the air passes to a cylinder III having a piston II 8 therein, the rod of which is connected to the joint II! of the toggle consisting of links H5, 5. As illustrated, the piston rod is pivoted at I20 to an angular arm I2I rigid with the link H6 and radial with the joint H0 of the toggle links H5, H5. The

cylinder III is shown as carried by the toggle link 82* and pivoted at I22 to a bracket I23 on the link 02' to have an oscillating movement. When air enters the cylinder II I and either or both manuals are released before the press completes its closing movement, the piston H8 is actuated to fold the toggle links H5, H5 even though the piston I8 in the main cylinder II continues its operation. Nevertheless, due to the folding movement of the toggle links '5, H6, the upper press head is retracted. The cylinder I I! and piston I I8 are the same as or corresponds to the cylinder and piston I05, I IIIv (Figure 3) In the general operation of the form shown fold the toggle links 28, 30, so that the lower element 2 is retracted and the operator can not get his hands or fingers injured between the dies 5, 6 When the shaft 1, however, completes its revolution and the clutch I0 automatically is thrown out, asin any conventional punch press,

whereupon the valve 35 closes, in Figure l, and the pressure within the cylinder 21 leaks out through the bleeder valve 54, permitting the spring 58 to again re-set the toggle links 29, 80. The machine is then ready for the next normal operation.

In the form shown in Figure 3, when the manuals I4, I5 are both properly operated, air enters the cylinder 11 to actuate the piston therein and close the press. The movement of the piston rod I9 opens the valve 35 through the lever 43 and therefore if the operator removes either or both hands from the manuals I4, l5 before the piston passes the port 91, air under pressure will pass from the feed pipe 39 through the valve 35, pipe 45, and one or the other of the piston valve chambers to the cylinder I08 and actuate thepiston I01 therein to fold the toggle links I03,

I04 and retract or pull downwardly the lower pressing element I3, so that there is no opportunity for the operator to get his hands burned or squeezed between the pressing elements upon the release of either or both hands. The air is free to exhaust from the diaphragm chamber 81 which operates the master valve back through the manual control valve, which has been released, and hence the press will open under the counterspring 85 and also the air will exhaust from the cylinder I06 operating the retracting toggle, back through the released control valves I3, I4 permitting the spring I05 to reactand re-set the toggle links I03, I04. Y

The operation of the construction shown in Figure 6 is the same as that shown in Figure 3, with the exception that the links or sections I I5, II5 of the toggle link 8| of the motion transmitting means between the piston in the main cylinder and the head-carrying lever I4, told when the operator releases either or both manuals before the press completes its closing movement and in so folding retract the movable press head instead of the normally stationary pressing element.

In any form, the retractile movement is relative to the prime mover and the prime mover continues its operating movement or is not disabled when the operator releases one manual before the press closes. In Figure l, the retracting movement of the element is relative to the prime mover shaft I, clutch I0 or the power shaft actuating the shaft I through the clutch I0. In Figure 3, the retracting movement of the lower pressing element I3 is relative to the piston prime mover I8. In Figures 6 and 7, the retracting movement of the upper press head is relative to the prime mover piston I8.

What I claim is:

1. In pressing machines which include coactaaasao'r ing pressing elements, one of which' has a closing and opening movement relatively to the other, 7

and power actuating'mechanism for the movable element including a prime mover; the combination of one of said elements-being retractable 6 by the prime mover, a two hand control includ- 1 erating the retracting means, the retracting ing independently operable manuals, both oi which must be operated Jointly to control the operation of the actuating mechanism, and means controlled by the release of either manual at an intermediate point in the closing movement of the movable element for operating the retracting means.

2. In pressing machines which include coacting pressing elements, one of which has a closing and opening movement relatively to the other, and power actuating mechanism for the movable element including a prime mover; the combination of one of said elements being retractable from its normal position relative to and during the closing movement, means operable independently of the prime mover to retract the retractile element during the closing operation by the prime mover, a two hand control including independently operable manuals,

both of which must be operated jointly to control the operation of the ac ting mechanism, and means operated by the actuating means during the closing movement of the movable element and controlled by the release of either manual at an intermediate point in the closing movement of the movable element for operating the retracting means.

3. In pressing machines which include coact ing pressing elements, one of which has an opening and closing movement, and power actuating mechanism for the movable element; the combination of one of said elements being retractable relative to, and during, the closing movement, means operable to retract the same, a

power control system for the actuating means and the retracting means, a two hand control including a pair of manuals, manually operable control'members in the power control system, both of which must be operated by the manuals to control the flow of ppwer to the actuating means, an additional control member in the power control system operated by a movable part actuated by the actuating means during the press closing movement and located to control the flow of power to the retracting means, a

when either or both manuals are released and the control member operated by the actuating means is so operated, whereby upon the release of either manual when the movable element is in the intermediate stage of its closing movement, the retracting means is energized through the transfer line.

4. The two hand control of claim 3 in which the power control system for the actuating means is a pressure fluid conduit system and the pair of manually operable control members and the additional control member are valves in said control system.

5. In a pressing machine including coacting pressing elements, one of which has a closing and opening movement relatively to the ,other,

and power actuating means for the movable element; the combination of means for retracting one of said elements relative to, and during,

the closing movement, a control system including independently operable manuals and control members operated thereby,'both of which must be opeiated jointly to control the operation of the actuating mechanism, and means controlled by the release of either manual and at-an intermediate point in the closing movement for opmeans including toggle links normally in straightened position and the means controlled by the release of either manual for operating the retracting means being connected to the toggle to fold the same 6. A pressing machine" including coactlng pressing elements, one of which has an open= ing and closing movement relative to the other, and power actuating mechanism for the movable element, one of said elements being retractable relative to the closing movement, during the closing movement, means operable to retract the same including toggle links normally arranged in straightened position, a control system including independently operable control members, both of which must be operated Jointly to control the operation of the actuating mechanism, a pair of manuals for operating the control members and an additional control member operated by the actuating mechanism during the closing movement of the movable element and controlled by the release of either manual at an intermediate point in the closing movement of the movable element for folding the toggle.

'7. In a pressing machine, coacting pressing elements, one of which is normally stationary and the other operable to close and open into and out of coaction therewith, and power actuating mechanism for; the movable element; the combination of said normally stationary element being retractable from its normal position, means operable to retract the same, a control system, independently operable manuals and control members operable respectively thereby to control the operation of the actuating means, and means controlled by the release of either manual at an intermediate point in the closing movement of the movable element for operating the retracting means.

B. In a pressing machine, coacting pressing elements, one of which is normally stationary and the other operable to close and open into and out of coaction therewith, and power actuating mechanism for the movable element; the combination of said normally stationary element being retractable'from its normal position, means operable to retract the same, independently operable manuals and control members operable respectively thereby, to control the operation of the actuating means, and means operated by the actuating means during the closing movement of the movable elementand controlled by the release of either manual at an intermediate point in the closing movement of the movable element, for operating the retracting means.

9. In a pressing machine, coacting pressing elements, one of whichis normally stationary and the other'operable to close and open into and out of coaction therewith, and power actuating mechanism for the movable element; the combination of said normally stationary element being retractable from its normal position, means to retract the same, a power control system for the actuating means and the retracting means, a pair of manuals and control members operated respectively thereby in the system, both 01 which manuals must be operated to control the operation of the actuating means, an additional control member in the control system operable by amovable part actuated by the power actuating mecha nism during the press closing movement'and located to control the fiow 01' power to the retracting means, a power transfer line connected to the additional control member and to the retracting means through the former control member, the transfer line being effective to transfer power only when either or both manuals is released and the control member operated by the actuating means, whereby upon the release of either manual, when the movable element is at an intermediate stage in its closing movement, the power is transferred through the transfer line to the retracting means.

10. In a pressing machine, coacting pressing elements, one of which is normally stationary and the other operable to close and open into and out of coaction therewith, power actuating mechanism for the movable element including a cylinder and piston motor, and motion transmitting means between it and the movable element; the

combination of said normally stationary element being retractable from normal position and means to retract the'same including. a cylinder and piston motor and motion transmitting means between the same and the retractable element, a fluid pressure conduit system to the first motor, a pair or manually operable control valves connected therein and manuals therefor, both of which must be operated at the same time to efiect the flow of power to the first motor, a power transfer system for the motor of the retracting means including a normally closed control valve, andmeans for opening it operable by a movable part of the motion transmitting mechanism during the closing movement, and a pair of normally open valves also operable by the manuals into position to cut oil the fiow of fluid to the retracting means when both manuals are operated and to permit the flow of power to the retracting means when either manual is released during the closing movement. Y

11. In a pressing machine, coacting pressing elements, one of which is normally stationary and the other operable to close and open into and out or coaction therewith, power actuating mechanism tor the movable element including a cylinder and piston motor, and motion transmitting means between it and the movable element; the

combination or said normally stationary element being retractable from normal position, means to retract the same including a cylinder and piston motor, motion transmitting means between the same and the retractable element, a fluid pressure conduit system to the first motor, a .pair or manually operable control valves connected therein and manuals therefor, both of which must be operated at the same time to efl'ect the fiow or power to the first motor, a power transfer system for the motor or the retracting means -01 the actuating means for holding the press --closed, when the movable element has traveled a predetermined distance toward closed position and for rendering the control member for the retracting means ineffective, and release means for the holding means.

'12. In a pressing machine, coacting pressing elements, one 01. which is normally stationary, and the other operable to close and open into and out 01 coaction therewith, and power actuating mechanism for the movable element; the

combination of said normally stationary element being retractable from its normal position, means operable to retract the same and hold it in norvmal position including toggle links normally arranged in straightened position, normally idle motor means operable to fold the toggle to retract the normally stationary element, manual means operable to control the operation of the actuating means, and means controlled by the release of the manual means at an intermediate point in the closing movement of the movable element and for controlling the 'energization of the motor 01' the retracting means.

ERNEST DAVIS. 

